Systemic lupus erythematosus (SLE) is a systemic autoimmune disease, with unknown etiopathogenesis and multi-organ involvement, characterized by autoantibodies that induce tissue damage. Dendritic cells (DCs) are the sentinels of the immune system sampling danger signals from the periphery. They produce proinflammatory cytokines, and interact with naive T cells in secondary lymphoid organs evoking an appropriate immune response, thus bridging the innate and adaptive immunity. We have shown recently that myeloid dendritic cells from the Sle 1,2,3 lupus-prone mouse model, show a Type I Interferon Signature that predates disease onset. Interestingly, we have discovered from a sample microarray analysis of bone-marrow-derived dendritic cells (BMDCs) from young pre-diseased lupus-prone Sle 1,2,3 mouse that many members of the kallikrein family of genes show very low expression as compared to the C57BL/6 wild type; the results have been validated by real-time PCR as well. Also Genome Wide Association Studies (GWAS) have recently revealed that the genes in the kallikrein family are associated with SLE, making this an important target in lupus pathogenesis. So far there has been no systematic study on the role of kallikreins on DCs and the impact on immune response and lupus autoimmunity. The overall goal of this project is to analyze the role of kallikrein-kinin system (KKS) in regulating he Interferon Signature in DCs and other immune cells and to study the impact of the KKS on lupus pathogenesis and provide insights to new therapeutic targets. Since their discovery over a century ago, kallikreins, a family of serine peptidases, are majorly known to have functions in regulating blood pressure, redox balance, fibrosis within the kidneys, inflammation and apoptosis. It is only in the last couple of decades that literature is beginning to accumulate evidence on the role of kallikreins in the immune system, especially that the kallikrein-kinin system can be a danger signal that can activate dendritic cells. With this background I aim to test (1) the effects of putative candidates in kallikrein-kinin system (KKS), specifically on Type IFN signaling and related pathways in dendritic cells and other immune subsets (2) if candidates of the KKS can ameliorate lupus disease.